The roughback whipray (Fluvitrygon kittipongi) is a rare
habitat degradation
and heavy fishing pressure within its limited range.
Taxonomy
The roughback whipray was described by
type specimen. Based on morphology, F. kittipongi seems to be most closely related to F. signifer, which shares its range.[2]
Distribution and habitat
The original five specimens of the roughback whipray were all caught from the
bottom-dwelling species inhabits main river channels at a depth of 5–20 m (16–66 ft). In contrast to F. signifer, which favors muddy bottoms, it appears to favor sandy to silty substrates.[1][4]
Description
The roughback whipray has a thin and oval
pectoral fin disc slightly longer than wide, with the anterior margins converging at a broad angle to the tip of the snout. The snout terminates in a small, protruding knob, which is relatively larger than in F. signifer. The eyes are small and immediately followed by larger, teardrop-shaped spiracles. There is a curtain of skin between the nostrils with a gently concave or lobed posterior margin. There are 4–5 papillae (nipple-like structures) across the floor of the small mouth. The small teeth are arranged in 4–5 series in the upper jaw and 14–15 series in the lower jaw; in some individuals, the outermost teeth are stained orange-brown. The whip-like tail lacks fin folds and bears one or two serrated, stinging spines on the upper surface, which are seldom found intact.[2]
The
dermal denticles are better-developed than those of F. signifer, with a central band of denticles covering the dorsal surface of the disc and tail base. There is also an enlarged "pearl organ" in the middle of the back that is present throughout life, and a row of enlarged denticles (some thorn-like) running from the pearl to the base of the sting. The disc is light gray or brown to dark orange-brown above, with a white to yellow spot just before the eyes and behind the spiracles, and sometimes a subtle, lighter band running around the margin. The underside of the disc is white, and unlike in F. signifer there is a dark (but not black) marginal band that extends from about one-third of the disc length back from the snout top, to the pelvic fins. The tail is gray to orange-brown above and white below at the base, becoming white with dark spots or nearly black past the sting.[2] A small species, the largest known specimen is a female 29 cm (11 in) across.[1]
Biology and ecology
All five original roughback whipray specimens bore extensive, healed wounds to the disc and/or pelvic fins, and had much of their tails bitten off such as that the remnant is only 1.3–1.8 times longer than the disc width (the tail of F. signifer measures over three times the disc width).
aplacental viviparous with females provisioning their developing embryos with histotroph ("uterine milk"). Males reach sexual maturity at around 25 cm (9.8 in) across.[4]
Human interactions
Uncommon and known only from a few locations, the roughback whipray faces intensive fishing pressure and is subject to
^ abcdefgVidthayanon, C. & T.R. Roberts (2005). "Himantura kittipongi, a new species of freshwater whiptail stingray from the Maekhlong River of Thailand (Elasmobranchii, Dasyatididae)". Natural History Bulletin of the Siam Society. 53 (1): 123–132.
